JPS57202179A - Automatic focusing device - Google Patents

Automatic focusing device

Info

Publication number
JPS57202179A
JPS57202179A JP56086936A JP8693681A JPS57202179A JP S57202179 A JPS57202179 A JP S57202179A JP 56086936 A JP56086936 A JP 56086936A JP 8693681 A JP8693681 A JP 8693681A JP S57202179 A JPS57202179 A JP S57202179A
Authority
JP
Japan
Prior art keywords
circuit
gain
output
dynamic range
amplifier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP56086936A
Other languages
Japanese (ja)
Other versions
JPH0258833B2 (en
Inventor
Yoshihiro Todaka
Kentaro Hanma
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP56086936A priority Critical patent/JPS57202179A/en
Publication of JPS57202179A publication Critical patent/JPS57202179A/en
Publication of JPH0258833B2 publication Critical patent/JPH0258833B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/67—Focus control based on electronic image sensor signals
    • H04N23/673—Focus control based on electronic image sensor signals based on contrast or high frequency components of image signals, e.g. hill climbing method

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Automatic Focus Adjustment (AREA)

Abstract

PURPOSE:To prevent malfunction due to deficient dynamic range, by switching the sensitivity of a detector detecting a video signal for automatic focusing at the upper and lower limits, and extending the dynamic range. CONSTITUTION:A light from a lens 1 is inputted to a step shape variable gain amplifier 10 from a terminal 3 as a video signal at a photoelectric converting circuit 2. A detector 5 is connected to an amplifier 10 and the gain of the amplifier is switched via an excessive output detection circuit 12 when the detected output is excessive and via a minimum output detection circuit 13 when the output is small. A latch pulse generating circuit 14 is connected to output detecting circuits 12 and 13, and a previous value held in a differential hold circuit 6 at the changeover of the gain is given to a motor driving circuit 7 to drive a lens driving motor 18. Thus, the malfunction at the gain switching is prevented, and the dynamic range of the detector 5 can be extended.
JP56086936A 1981-06-08 1981-06-08 Automatic focusing device Granted JPS57202179A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56086936A JPS57202179A (en) 1981-06-08 1981-06-08 Automatic focusing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56086936A JPS57202179A (en) 1981-06-08 1981-06-08 Automatic focusing device

Publications (2)

Publication Number Publication Date
JPS57202179A true JPS57202179A (en) 1982-12-10
JPH0258833B2 JPH0258833B2 (en) 1990-12-10

Family

ID=13900748

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56086936A Granted JPS57202179A (en) 1981-06-08 1981-06-08 Automatic focusing device

Country Status (1)

Country Link
JP (1) JPS57202179A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60143072A (en) * 1983-12-29 1985-07-29 Matsushita Electric Ind Co Ltd Automatic focus matching device
JPS60143070A (en) * 1983-12-29 1985-07-29 Matsushita Electric Ind Co Ltd Automatic focus matching device
JPS60143071A (en) * 1983-12-29 1985-07-29 Matsushita Electric Ind Co Ltd Automatic focus matching device
JPS63500405A (en) * 1985-10-29 1988-02-12 エドガル・イルゲン A computing device that operates based on electronics.

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60143072A (en) * 1983-12-29 1985-07-29 Matsushita Electric Ind Co Ltd Automatic focus matching device
JPS60143070A (en) * 1983-12-29 1985-07-29 Matsushita Electric Ind Co Ltd Automatic focus matching device
JPS60143071A (en) * 1983-12-29 1985-07-29 Matsushita Electric Ind Co Ltd Automatic focus matching device
JPS63500405A (en) * 1985-10-29 1988-02-12 エドガル・イルゲン A computing device that operates based on electronics.

Also Published As

Publication number Publication date
JPH0258833B2 (en) 1990-12-10

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